Knee Joint Cartilage Observedin Polarization Light and under the Transmission Electron Microscopes

Overview

Microstructural changes of the joint cartilage are a significant morphological correlate of patholo-gical process. Successful detection of their primary symptoms requires both detailed knowledge ofstructure of particular cartilage layers and the use of suitable histological techniques. In theliterature there are fundamental discrepancies in the description of the superficial chondralmembrane (lamina splendens) as well as in the orientation of collagen fibrils running in thehorizontal layer and their attachment in the lamina splendens. We investigated the horizontal layerof the hog knee cartilage with respect to the lamina splendens. For orientation in the whole thicknessof the joint cartilage, sections stained for collagen were studied under the polarization microscope;the course and the orientation of particular fibrils are apparent in the transmission electronmicroscope. The clearly distinct lamina splendens appears as a homogeneous acellular layer underthe polarization microscope, being finely granular with fibrils running in all directions parallel tothe articular surface in the transmission electron microscope. The resultant model is used for thedescription of articular cartilage surface changes after experimentally introduced fissures (splitline).

Key words:
joint cartilage, lamina splendens, split line